Method and apparatus for coordinating radio and phonograph reproduction



June 21, 1932. R A FESSENDEN 1,863,841

METHOD AND APPARATUS FOR COORDINATING RADIO AND PHONOGRAPH REPRODUCTION Original Filed May 21, 1924 Fig-1- TD TELEPHUNELINE 20 A F'HUNU ELEETRIE GENERATOR Fig.1

J3 f4 60 J 52 2: 079 if If a7 I BRIDGE 7 TD TRANSMITTER DR RECEIVKR;

63 VI El LIN b Pk/ENTER:

WWI 1 04 W ELIE:

Patented June 21, 1932 UNITED. STATES PATENT OFFICE REGINALD A. FESSENDEN, OF CHESTNUT HILL, MASSACHUSETTS, ASSIGNOR TO SUB- MAR INE SIGNAL COMPANY, OF PORTLAND, MAINE, A CORPORATION OFMAINE METHOD AND APPARATUS FOR COORDINATING RADIO AND PHONOGBAPH REPRODUCTION Original application, filed May 21, 1924, Serial No. 714,899. Divided and this application filed September 13,1927. Seria1N0.219,351.

My invention relates to improving the efiiciency of radio and wire telephone and phonograph reproduction, and more especially to co-ordinating these methods of reproduction, (and similar means, as reproduction from different radio stations), and still more especially to convenience in said co-operation and to the production of new effects and results thereby. a

The object of my invention is to accomplish said increase in efliciency and said coordination, and said convenience in coordination and operation, and said new effects and results.

The accompanying drawing shows, partly diagrammatically, means adapted for thecarrying out of my invention.

Figure 1 shows the arrangement of apparatus and circuits.

Figure 2 a type of electric generator adapted for use with my electro-phonograph an Figure 3 shows the application of the invention to a violin in detachable form in its relation to a violin bridge.

This application is a division of U. S. ap-

' lication Serial No. 714,899, filed May 21, 1924.

In Fig. 1 is shown a novelsystem in which a radio or wire telephone and a phonograph act individually or in conjunction, and without any necessary mechanical connection between the phonograph record and the device emitting the sound, i. 0. here shown as 'a piano 39. Here is the phono-electrio generator, whereby the minute electric impulses are produced in the circuit 37 34, by the relative motion of the record 28, either optically as shown in U. S. applications Serial No. 685,699, filed March 23rd, 1912, and- Serial No. 42,856, filed July 29th, 1915, and Serial No. 635,362, phonogra'ph-kinetoscope, filed July 26th, 1911, and Serial No. 423,186, filed Nov. 10th, 1920, (but which optical methods and apparatus are not claimed herein) or as shown, and more 'fully and in detail in Fig. 2, me-

I chanically by the action of the phonograph needle 8; or In any other suitable manner.

. The disc 28 is driven by the electric motor 36, whose speed is regulated as desired by the reproducer;

the adjustable resistance 37, or other suitable means; 37 is an adjustable impedance for regulating the strength of the electric impulses in the circuit, and hence the strength of the reproduction in the piano-speaker 39.

30 is the circuit of the wireless or wire telephone line; 33 is an amplifier operating the piano speaker 39, described below. 34 and 30 are transformers for putting the phonoelectric generator and the telephone circuits in operative relation to the amplifier.

32 is a switch. When it is thrown to the right, on to the contact 32, the wireless telephone is cut out, and only the phonograph record is heard. When it is thrown to the left, to contact with 33, the phonograph is cut out and at the same time, by reason of the insertion in the circuit thereby of the compensating coil 33', the tuning of the wireless circuit is maintained unchanged. When the switch is in the intermediate position, as shown, both wire less and phonograph act oonjointly and a soloist on the wireless may be accompanied by a full orchestra on the phonograph, or vice versa, speed being regulated by 37 and relative intensity by 37. is a switch whose function is described below.

Fig. 2 shows a suitable form of phonoeletric generator more in detail. Here a coil 210 of light weight is fastened to the phonograph needle, as shown, moved back and forth in the field of the magnet 190 by the motion of 8, pivoted at 27 and actuated by the revolving phonograph disc 28, generates currents which are carried to the reproducer 18, as shown. I

By this invention a' number of entirely new and very useful results are obtained, e. g.

It enables one to accompany a broadcast solo by McCormack, That Old Refrain for example, by a phonograph record of Kreislers (the composers) rendition on the violin of the same composition, and to modulate the strength of the accompaniment at every instant. and instantaneously, to suit the molnentarily varying strength of the broadcast of the soloist; the tempo being similarly varied to coincide with that of the broad-- cast; or to supplement the rendition by Damor other suitable means,

and being rosch and his orchestra of Evenin Star: from Tannhauser over the radio by arusos voice from a phonograph record; or to hear Caruso and McCormack sing together the same famous song, a possibility of great value in the study of singing.

other by an electromagnetic mechanism, or-

there are disturbing impulses. v

The listener may himself accompany the radio or phonograph by playing on the piano, and the effect is much more natural and agreeable, as'both sounds come from the same location in the room. The desired changes in modulation may be made instantly and by one seated at a distance, in place of one stand ing beside the phonograph loud speaker; and without danger of injuring the record, by merely shifting the element 37'- Another advantage is in shifting phonograph records at a distance from the loud speaker without the necessity of employing special mechanism. One may be'seated in a chair on the opposite side of the room from the piano loud speaker, and listening tothe radio. A broadcast may come in which might be accompanied by a phonograph record. If

the phonograph motor and disc table is at the elbow, all that is necessary to place the desired disc on the rotating table, and ad-,

just the s eed and then the modulation by moving 3 37. And the modulation may be made such that the phonograph record is reproduced many times louder than any standard type of phonogra h could do, or adjustedinore delicately an softly, or loudly and softly on. the same record, to accompany the radio, without moving from the seat. And if the micro-photo-phonographic records are used, described and claimed in SerialNo. 423,186, filed Nov. 10th, 1920, the storage and handling and costs of the records is much reduced.

The type in which an independently playable musical instrument with strings such as a piano is used, enables the listener to acc0m-' pany either the radio or the phonograph or both combined, himself. This is of. great value to students on these instruments;

A student can compare his own touch on the piano with that of the greatest livin" masters of the art; or of those long dead. By the use of an area source,-such as the piano,

the necessity of having the phonograph disc driving apparatus and the radio apparatus the phonograph discs may be more conveniently located near a fire place or electric reading lamp. Or one member of the householdiwho may prefer to sit in one place, may

prefer'the radio and another, who may prefer to sit in another, may prefer the honpgraph. With the area source, both wi hear 0th reproductions equally well, no matterwhere they may sit. I

By the use of the piano as loud speaker, absolutely correct reproduction is obtained and static and scratching is cut out.

By this system the power required for driving the phonograph discs is much reduced and the whole outfit may be driven from dry cells; a matter'of importance where no electric power circuits are available.

It is preferred that the thrust of the moving part of the electromagnetic or other mechanism which operates the loudspeaker against the diaphragm or its equivalent should be opposed, not'by a s ring or other device having a natural perio but as shown in Fig. 5 of the parent ap lication, by inpiano is played upon, the loud speaker mechanism acts as 'a generator and the music played is transmitted through the circuit 46 to any place desired, for example to another roomin the h fuse. p This reverse action of electromagnetic mechanism is well known. An example is the tclephonereoeivr which may be used to transmit electric waves as well as to produce sound waves. When acting as a producer of electric waves, all that is necemary is to have an initial magnetization of the wire, 43. If it is not desired to-do this b permanent magnetization, it may be done iiy passing a slight direct current in the coil 50. The wire 43 havin its magnetization or permeability changed y the action of the acoustic waves on it varies the flux threading the coil 50 and thereby induces an electromotive force in it corresponding to the acoustic waves. In this manner the iano may act as asource of sound in pro ucingelectric currentand may" therefore be said to generateelectromagnetic waves.

By the term electro-phonograph is meant a phonograph in which the recorded sounds are first transformed into electric impulses before being produced; and includes the Ill elements nece ary for generating the elec out scratching, static, and abrupt disturbin impulses generally, by the use of a plu-.

ra ity of resonant elements, discovered that even a violin, with only four strings, though not cutting out static to any useful extent,

- when used as a loud speaker for electricphonographs, cut out a part of the scratching rom the phonographdiscs. Applicant then discovered (amongst other ways) that by adding additional resonant elements, for example, reads attached to the violin bridge,

substantially all the scratching could be cut out. He further found that if the number of reeds was made sufficiently numerous, such a violin loud speaker would even cut out substantially all of the static when used for re ceiving radio broadcasting.

Applicant then discovered that a piano could be used for receiving radio broadcastmg, and that it had a sufficient number of resonant elements attached to its sound board,

as they listened in on other types'of apparatus, to ascertain the atmospheric conditions. Reports of other tests, e. g, by the U. S. Navy, will be found in the Boston American for August 28, 1924, with photographs of the apparatus and description of the mechanism attaclhed to the back of a piano, and other detai s.

The piano loud speaker 39 of Figure 1 may have its sound board set in vibration by the electric telephone impulses in any suitable way, since the essential feature of its efficiency as a loud speaker lies in the conjunction of the sound boardwith the plurality .of resonant elements, i. e. piano wires. In most cases, e. g. as in the Boston American reference to August 28, 1924, any good speaker mechanism is simply wired into the back of the piano, and its vibrating element fastened to the back of the sound board.

Fig. 3 shows another form. Here 50 is a violin and 51 is its bridge; 55, 55, 55, 55, are the violin strings. 52, 53, 54 are vibrating reeds, weighted on the ends as shown and of such dimensions, best; found by experiment, that they have a predetermined amount of dampening, preferably, in most cases, an amount approximately equal to that of the violin strings; and attached to the bridge, as shown. The natural periods of the auxiliary vibrators 52, 53, 54 are preferably different from those of the strings and preferably above and below those ofthe strings.

The;violin is preferably driven or excited by a sldeways pull of the wire' 59, as applicant has discovered, contrary to what has heretofore been taught, that the main mode of action of a violin is a-rocking of the bridge and not an up and down motion, and that the efiiciency of a violin can be much increased by attaching a vertical strip of thin wood to the underneath side of the top of the violin, and running longitudinally, so :as to act, as a sort of a fan When the bridge isrocked' in playing.

The wires 59 and 59' are preferably of soft iron or nickel and are screwed into the circular spring 60, of magnetic material, so as to leave a small air gap between them, as shown. 22, 23 are as before a magnetizing coil and a source of current and 61 is a coil connected as shown to leads 63, leading to the transmitter, or receiver. 62 is a small ball, used as an inertia-to oppose the pull on the bridge when the two wires 59, 59 are attract- .ed togetherbythe action of the currents flowing in the coil 61, coming from the transmitter.

Similarly, when the violin is played upon, the wire 59 approaches and recedes from the wire 59, thereby generating electric currents which flow out into the line 63 and ac-.

tuate the receiver.

Applicant has, by means of his Wollaston wire galvanometer, described'in U. S. Patents 979,145 and 1,045,782 and elsewhere, plotted curves showing the sound efficiency of different musical instruments at different frequencies; and has found that the violin and piano have substantially straight line efliciency curves, and horizontal i. e. the efficiency of these instruments (and also, approximately, that of the violincello and bass viol) is substantially constant over their range. Applicant has also found that these act as area sources and consequently when arsubstantially, independent off their location.

And in taking phonograph records of sing ers and orchestras, there is no necessity of the singer leaning backwards and forward as he sings, or of placing the instruments in definite positions. And in reproducing all those in the room can hear substantially equally well. i

Applicant has found that the pick-up and reproduction of these instruments so ar ranged and employed as shown, and in similar manner, is immeasurably better as regards articulation and .naturalness of tone than-the lould speakers on the market: \Vith this form of pick-up and reproducerthe speech and slngin g are indistinguishable from those of the individual when in the room.

Applicant has dlscovered that owing to the By the expression operable selectively r 1. In a system" of the that abrupt noises donot act in sustained synchi'onism, and hence do not setthe vibrating elements swinging to anythinglike the degree that-sustained vibrations do. In the violin, e. g. when arranged as shown and de scribed, and acting as loud speaker, the noises coming in on a night of bad atmospheric are not only changed from a low itched rumble and crash to a few crackles, ut the pitch is raised substantially above that; of the highest string on the violin. And byapplying several vibratin elements of pitches approaches inaudibility, as 53, 54, in Fig. 6, the disturbances remaining are substantiallytoo high pitched to be substantially appreciable, and thebroadcast comes in veryiplainly.

Better results are, however, obtained b the arrangement shown in Figure 1 in whic a nickelor iron "wire 43 is fastened at each end to adjustable tuning pins 41, 42, stretched over bridges 40, and the received'telephonic currents flowing through the coil vary themagiietization'of the, wire 43, and change its length by the well known magnetostriction effect, thereby bending thesoundboard in and out, and causing the whole soundboard to act as a'unitary large diaphragm. By employing a number of such wires 43, and suitably arranging them, as

shown in another co-pending application,the

piano. sound board and wires are made so that they have. no detrimental selective resonance. The advantage of using the adjustable tunin pins 41, 42, isthat by proper stretching o the nickel wire, the magnetostriction efiectis greatly improved, and made uniform.

by the phonograph or wireless, is meant operable b either one or the other, as desired.

By the term operabie jointly is meant 0 erable by bothof them togetherand simdltaneously. By area source of sound I mean source of the kind described in my U. S. Patent 1,277,562, Sept. 3rd, 1918, -1. e. havin a diameter of more than seven inches. y the combination herein described new technical effects are produced. p WhatI claim as my invention is kind described, a pick up device includingan area source and a plu rality of substantially parallel resonant elements'operated directly thereby, said pick up device including a vibratable element ar- 1 ranged substantially perpendicular to said resonant element.

2. In a system of up device including a violin having a bridge and a vibratable element attached thereto and operated in the longitudinal direction of said bridge.

3. In a system of the kind described, a pick up. device comprising a violin having a /brid'ge, a resonant element contacting therewith 'and "a current varying device operated directly by said bridge.

. 4. In a system of the kind described, a pick the kind described a pick up device comprising a violin having a bridge, a resonant element contacting therewith and a, magnetophonic pick up unit h avibngdits vibratable element attached to said 5.' In a system of the kind described,- a pick up device comprising an area source having a plurality of resonant elements extending one way and a magnetophonic pick up unit having its vibratable element operatively connected with said resonant element, said vibratable element vibrating in a direction transverse to said resonant elements.

' 6. In a system of the kind described, a

. loud speaker having a plurality of resonant elements, a bridge on which said elements rest, and a loud speaker unit having its vi- -bratable element attached to said bridge element. a

7. In a system of the kind described a loud speaker including a violin and a loud speaker unit having its vibratable element attached to said violin. v r Y 8. In a system of the kind described, a loud speaker including a violin and a loud speaker unit having its vibratable element attached to the brid e of said violin.

9. In a system 0 the kind described, a loud speaker including a violin and a loud speaker l1111l3 having a lon 'tudinally vibratable rod attached at one en to the bridge of said violin and at the other. end to means for lmpressing"com%essional waves thereon.

EGINALD A. FESSENDEN. 

